Wavy floor on OSB (that was soaked before install)

Q: My engineered hardwood flooring is very wavy. The house is only a year old. The OSB subfloor was exposed to water, ice and now and was never swept off. Do you think the subfloor has been compromised? The OSB has a exposure 1 rating.

A: I’m not really sure what you mean by wavy. Do you mean the edges of the boards are raised, called cupping? Is the floor nailed down or glued?

Follow-up: The wavy floor is neither cupping or crowning. Actually the seams and joints are fine. The RH level in the house is running perfect. The floor has multiple depressions. The flooring is engineered hardwood nail down. I also forgot to mention that the OSB subfloor was saturated for 3 months plus. It was never swept off or snow never completely melted away in that time frame.

A: It’s quite possible the edges of the OSB sheets are not flat though it must have been dry when the floor was installed or you would have had problems with cupping at least. Not really a fan of OSB personally. And who knows what kind of job the framers did with the floor joists. Maybe not so good. I’ve worked in new houses where the sub floor was not flat in spots though plywood was used. This can only be from sloppy framing. We had to shave some of the plywood down with a planer.

Follow-up: Thanks for your input, I was thinking the same thing.

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